if it takes 8 hours, chances are you are using the wrong product. use a bleaching product first, i know l'oreal makes one called blondissima. then after you bleach, use the garnier haircolour to achieve the colour you want.
if you have brown hair (i'm not sure of the shade) and have a hard time taking it blonder, chances are that blonde isn't the best colour for you. a light brown/caramel shade would probably look much more natural, and be easier to achieve and maintain. saying this, i don't know you and i don't have a picture of you, so i may be wrong, but usually brunettes don't have the right skin colouring to pull off blonde hair.
I leave mine on for maybe an hour. I was blonde as a child, and probably medium brown if natural. My hairdresser told me that it ceases to lift after about an hour. Drugstore colors are made to shut off after a certain amount of time. Look at the 1-800 number on the back of the box and call it. They can tell you for sure! I don't have $75-80 to spend on highlights either. I hope to grow my hair out like you mentioned, ultimately ending with just highlights, but I like a lot of blonde and am very picky about roots, and I would have to have mine done at least every six weeks, or sooner. That's a lot of moolah!
Hint: I use a cheap, plastic shower cap while my color is processing. The heat increases the process. That is why most stylists will cover your head and put you under a dryer when they color your hair.
Also: Water affects the bleaching effect, so if you are sweating (who isn't right now?) your hair may not process as well.
For those of you wanting highlights but not wanting to pay the salon prices, you can buy a highlighting cap at the drug store. I have pulled my own hair through myself many times. You need a few mirrors to do it comfortably, or get a friend to help.
I wouldn't use the blondissima on your hiar too often. I have tried it a few times and it is really drying.
You are correct. I have had my husband pull out the back of my hair for me. You can also get really good, reusable rubber frosting caps, with needles, at the beauty supply store, or online, I'm sure. They offer a variety of sizes. I've thought of getting them often enough. I don't know why I haven't gotten one. I do my kiddoes' hair periodically.
ok, here is the real deal from a haircolorist in nyc. pretty much haircolor has done it's job of lightening and depositing after 45 minutes. shorter time will simply give you a slightly less deposit of color. in the lighter blonde shades there is more lift and alot less deposit of color. Most haircolor (with the exception of bleach--which i absolutely do not recommend at home after seeing many disasters over the years) is meant to control tone going 2 levels lighter, 3 max. This 2 level rule is particularly important if you are trying to control orange/red/chicken fat yellow. So start by picking the right shade. This takes a little time and energy, as most people don't have a clue as to their natual starting level. Try finding real hair swatches at a beauty supply place as opposed to box (distorted) swatches. This you only need to do once. When you have your starting point (also known as your level) then pick something 2-3 levels lighter with the right tone (ash to control orange etc, and the other tones are self explaining). after your initial application try only doing the roots each time, perhaps pulling through for a few minutes every 3 or 4 times. If this color is not light enough, keeping it on longer is not the answer. You need highlights (which will also make the hair look more natural). God has taste and all his hair color comes in gradations and tones. Nothing to me screams cheap than an all over bottled blonde with no deminsion. If you are doing it yourself I guess the way to go would be a cap. Always remembering that less is more and you can always go back to do more. If you ****** this up, please go see a professional to fix it. And I would probably find and interview this person before you have a mishap. Most good colorist do give consultations. I have corrected many botch up by so called professionals. Stop someone who's hair you admire and ask. From classes I attend and teach, I can tell you ever town has someone that is good and give a s***. Find this person out.